Science has also shown that the human sense of smell goes directly into the brain and encodes one of the most powerful kinds of memory. These "olfactory" memories evoke strong positive or negative emotional reactions. In Post-Traumatic Stress Disorder, flashbacks, anxiety, panic attacks and intrusive memories are frequently triggered by smells.
It is a smell's ability to evoke a powerful emotional response and whether or not this reaction could be used to help people with PTSD, that two Israeli doctors decided to research. Dr. Eitan Abramowitz of the mental health division of the Israeli Defense Forces and Dr. Pesach Lichetenberg of Herzog Hospital and the Hadassah Medical School of the Hebrew University in Jerusalem, undertook a three-year study of what they call "hypnotherapeutic olfactory conditioning (HOC)" and its effectiveness at treating PTSD in combat veterans.
Despite the lengthy, academic name, the treatment is really quite simply stated. The ability of scent to trigger emotional reactions is used to encode positive associations with the pleasant smells in the patient. When the patient is hypnotized, he or she is taught to associate these smells with a sense of well-being, safety and self-control.
At the end of the study, the results showed that these new associations could be used effectively to prevent panic attacks, anxiety and other symptoms common to Post-Traumatic Stress Disorder. The implications for these results could change the lives of men, women and children around the world who are living with this terrible illness.
You can read more about the study in the International Journal of Clinical and Experimental Hypnosis, Volume 57, Issue 2 April 2009, pages 184-197.